With the advent of lasers, people gradually realized that they have strong advantages such as high brightness, monochromaticity and directionality, and they have played an important role in scientific research, military, communications and other fields. Welding technology combines with laser to form a new waterproof laser pointer welding technology, which can effectively break through the limitations of traditional welding technology, and is therefore actively used in automotive manufacturing, aerospace and other fields.
Secondly, laser welding technology has also been widely used in medical and health applications. Due to the demanding requirements of the high cleanliness of its manufacturing process, laser welding technology meets its needs. Compared with other commonly used welding techniques, the laser welding technology produces almost no welding slag and debris, and it is not necessary to add any adhesive during the welding process, so that the entire welding work can be completed in the clean room. The addition of laser welding technology has greatly promoted the development of medical devices, such as the housing of active implantable medical devices, radiopaque markers for cardiac stents, earwax protectors, balloon catheters, etc. .
Implantable medical electronic devices, such as cardiac pacemakers, implantable electrocardiographs, and neurostimulators (spinal cord stimulators, deep brain stimulators, and implantable cochlear implants), are used to manage and treat the body's physiology Conditions such as heart rate, chronic pain, Parkinson's disease or severe deafness. In the past decade, patients have rapidly increased the use of implantable medical electronic devices at double-digit rates in order to improve the quality of life. These implantable electronic devices typically consist of microelectronic circuits and batteries that provide energy. In order to protect microelectronic circuits and batteries, they need to be sealed in a metal case. If the seal is lost, the body fluid can directly penetrate into the metal package, causing short circuit failure of the microelectronic circuit and endangering the patient's life.
Laser welding technology is the most common connection and sealing technology for implantable medical devices. The metal casing of implantable medical devices generally uses titanium and titanium alloys, but titanium has a strong ability to absorb hydrogen, oxygen and nitrogen at high temperatures, so the military laser pointer welding process needs to be carried out in an inert gas-tight environment. In laser welding, the control of laser energy plays an important role in the quality of welding. The laser illuminates the metal surface, which initially reflects 60% to 80% of the laser energy. As the temperature increases, the metal absorbs the laser energy gradually. When it reaches the boiling point, it can absorb nearly 90% of the energy.
The cardiac stent, also known as the coronary stent, is a commonly used medical device in cardiac interventional surgery and has the function of dredging arterial blood vessels. The main material is stainless steel, nickel titanium alloy or cobalt chromium alloy. During the process of transmitting the heart stent to the destination, the radiopaque lines at both ends of the stent can clearly see its trace and open state. The radiopaque markers can be made of precious metals such as gold, enamel and platinum iridium. Riveting, this molding process uses a green laser pointer with a minimum spot diameter of 40 μm (0.04 mm) to weld a disc-shaped marker into a special eyelet.
The gastroscope biopsy forceps used in medical treatment need to penetrate deep into the patient's body. Therefore, the quality of the biopsy forceps is very demanding. Each component of the composition needs to meet certain tensile strength and good appearance, especially the surface is not allowed. Glitch and other situations. In the previous production process, the front end of the gastroscope biopsy forceps is combined with riveting, resistance welding, etc., and the riveting method will leave burrs and other defects on the surface of the puncture gun, and resistance welding will also produce parts. The large deformation affects the practical application of the puncture gun, and the laser welding technology has the characteristics of non-contact processing, narrow heat influence range, high efficiency, high processing precision, etc., which can realize the flawless, no groove and no crease of the medical field. No burr and no cracking requirements.
Balloon catheter laser welding is the use of laser as the source of energy for infrared welding, which can be directly applied to the surface of the plastic that absorbs the 488nm laser pointer using a laser beam to melt the plastic for welding. The advanced laser welding technology can realize the seamless connection between the balloon tip and the tube body, so that the balloon catheter can be unimpeded when propelled in the curved and narrow diseased blood vessels, the damage to the blood vessel is minimized, and the operation process is safer.
The introduction of laser welding technology is beneficial to further reduce the outer diameter of the balloon dilatation catheter tip. A schematic diagram of the laser welded balloon catheter is shown in Fig. 8. Unlike metal welding, plastic laser welding requires less laser power. The greater the welding laser power, the larger and deeper the heat-acting zone on the plastic part will cause the material to overheat, deform, or even damage, so the laser power should be reasonably selected according to the depth of melting required. The use of plastic laser welding technology in medical devices is far more than the above applications. Plastic laser welding technology is being adopted by more and more medical device manufacturers, and its application prospects will be very bright.
In addition to the application of laser welding technology to the production of medical equipment, there are many other innovative usb laser pointer processing technologies that have great potential in the manufacture of medical equipment, such as laser surface modification, laser cutting, laser drilling and laser micromachining. Research and use of advanced laser processing technology will design more high-quality, high-demand medical equipment.